The present invention generally relates to a seat belt device for use in a motor vehicle and more particularly, to a seat belt device for a front seat provided in a motor vehicle, in which the getting on and off a rear seat is executed after the front seat has been shifted frontwards and a securing point where the seat belt of the front seat is secured to a vehicle body is located at a side portion of a seat cushion thereof. In the seat belt device of the present invention, when a person gets on or off the rear seat, such securing point of the seat belt can be shifted to a location not to interrupt the getting on and off.
In a motor vehicle having two doors in which the getting on and off the rear seat is executed by shifting the front seat frontwards, an opening for the door tends to be widened in order that the getting on and off the rear seat can be readily effected.
As shown in FIG. 1, the motor vehicle as referred to above is generally provided with a seat belt 55 having one end wound up in an emergency locking retractor 56, an intermediate portion supported by a lap anchor 57 and the other end fixedly mounted on a seat belt anchor 58 for functioning as the securing point of the seat belt on the side of the vehicle body. In such seat belt device, the seat belt anchor 58 is required to be provided at a location near the front seat 51 so that the seat belt device may ensure a certain holding force and the seat belt 55 may be readily mounted or dismounted. Accordingly, in the case where an opening portion D is widened, since a portion of the seat belt 55 passed between the lap anchor 57 and seat belt anchor 58 crosses substantially vertically in the opening portion D, the portion of the seat belt 55 occasionally undesirably catches a foot of the person who is about to get on or off the rear seat.
A seat belt device having a movable seat belt anchor has recently been developed to solve the above described problem and is disclosed, for example, in the Japanese Utility Model Laid-Open Application (Jikkaisho) No. 58-35443. More specifically, as shown in FIG. 2, such seat belt anchor 58 is freely reciprocably mounted on an anchor rail 59 extending in the longitudinal direction of the vehicle body. In the case where a person who sits on the front seat 51 puts on the seat belt 55, he is requested to draw it towards him to move the seat belt anchor 58 frontwards. On the other hand, in the case where a person gets on or off the rear seat, it is necessary for him to push or pull the seat belt 55 backwards to transfer the seat belt anchor 58.
In the aforementioned seat belt device, since the seat belt anchor 58 is disposed reciprocably in the longitudinal direction of the vehicle body, it can be transferred backwards so that a portion of the seat belt 55 passed between the lap anchor 57 and seat belt anchor 58 may be retreated backwards beyond the rear end of the opening portion D, thus resulting in that the getting on and off the rear seat is facilitated to some extent. In this kind of the seat belt device, however, since the seat belt anchor 58 is transferred backwards by holding the seat belt 55 extending between the lap anchor 57 and seat belt anchor 58, the seat belt anchor 58 can not always be transferred backwards. Accordingly, the seat belt 55 occasionally undesirably exists in his way to or from the rear seat and the person who is about to get on or off the rear seat is subject to a problem such that his foot occasionally gets caught in the seat belt 55.